1 /* ftruncate emulations that work on some System V's.
2 This file is in the public domain. */
15 ftruncate (int fd, off_t length)
17 return fcntl (fd, F_CHSIZE, length);
20 #else /* not F_CHSIZE */
23 /* By William Kucharski <kucharsk@netcom.com>. */
25 # include <sys/stat.h>
29 ftruncate (int fd, off_t length)
34 if (fstat (fd, &filebuf) < 0)
37 if (filebuf.st_size < length)
39 /* Extend file length. */
40 if (lseek (fd, (length - 1), SEEK_SET) < 0)
43 /* Write a "0" byte. */
44 if (write (fd, "", 1) != 1)
50 /* Truncate length. */
55 fl.l_type = F_WRLCK; /* write lock on file space */
57 /* This relies on the *undocumented* F_FREESP argument to fcntl,
58 which truncates the file so that it ends at the position
59 indicated by fl.l_start. Will minor miracles never cease? */
61 if (fcntl (fd, F_FREESP, &fl) < 0)
68 # else /* not F_CHSIZE nor F_FREESP */
69 # if HAVE_CHSIZE /* native Windows, e.g. mingw */
72 ftruncate (int fd, off_t length)
74 return chsize (fd, length);
77 # else /* not F_CHSIZE nor F_FREESP nor HAVE_CHSIZE */
82 ftruncate (int fd, off_t length)
88 # endif /* not HAVE_CHSIZE */
89 # endif /* not F_FREESP */
90 #endif /* not F_CHSIZE */